A hydrogen fuel cell stack(terminal voltage 9V) has an internal resistance of 1 Ohms. It is connected to hydrogen and oxygen reservoirs. It is being charged using a battery of 11 V terminal voltage and 1 Ohms internal resistance. a. How many moles Hydrogen are produced per second? How long does one have to charge to store 10kJ in chemical energy (the energy content of hydrogen is 242 kJ/mol of Hydrogen)? b. What is the conversion efficiency from chemical energy in the battery into chemical energy of hydrogen? c. Now the fuel cell is used as a source to operate a device w/ 5 Ohms resistance. What is the power consumed by the device? What is the conversion efficiency from Hydrogen-chemical-energy into energy consumed by the device?
1
